Automatic start and stop of a portable engine driven power source

ABSTRACT

The present embodiments provide a control system and method that is able to automatically start and/or stop a portable engine-driven power source. For example, in one embodiment, a system includes an engine-driven power source having an engine, a compressor driven by the engine, a sensor configured to generate a first signal indicative of a demand for air pressure from the compressor and a second signal indicative of no demand for air pressure from the compressor. The engine-driven power source also includes a controller configured to stop the engine in response to the second signal.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a Continuation of Continuation application Ser. No. 14/153,750,entitled “Automatic Start and Stop of a Portable Engine Driven PowerSource”, filed Jan. 13, 2014, which claims priority to U.S. Pat. No.8,627,797, entitled “Automatic Start and Stop of a Portable EngineDriven Power Source”, issued on Jan. 14, 2014, which claims the benefitof U.S. Provisional Patent Application Ser. No. 61/186,156, entitled“Automatic Start and Stop of a Portable Engine Driven Power Source”,filed on Jun. 11, 2009, both of which are herein incorporated byreference in their entireties.

BACKGROUND

The invention relates generally to power management for an enginecoupled to loads. More specifically, the invention relates to automaticstart and stop features for a service pack having an engine drivingvarious services, such as an air compressor, an electrical generator(e.g., a welding generator), a hydraulic pump, and possibly other loads.

Some work vehicles may provide auxiliary resources, such as electricalpower, compressor air service, and/or hydraulic service that are poweredvia one or more engines, such as the vehicle engine. Of course, theseintegrated auxiliary resources rely on operation of the one or moreengines for power. Some engines, such as the main vehicle engine, can belarge engines, which are particularly noisy, significantly over poweredfor the integrated auxiliary resources, and fuel inefficient. Further,other smaller engines can also be fuel inefficient at times. Forexample, an operator typically leaves the one or more engines idling forextended periods between actual use of the integrated auxiliaryresources, simply to maintain the option of using the resources withouttroubling the operator to start and stop the engines. Such operationreduces the overall life of the engines and drive train for vehicletransport needs.

BRIEF DESCRIPTION

Certain aspects commensurate in scope with the originally claimedinvention are set forth below. It should be understood that theseaspects are presented merely to provide the reader with a brief summaryof certain forms the invention might take and that these aspects are notintended to limit the scope of the invention. Indeed, the invention mayencompass a variety of aspects that may not be set forth below.

The present embodiments provide a control system and method that is ableto automatically start and/or stop a portable engine-driven powersource. For example, in one embodiment, a system includes anengine-driven power source having an engine, a compressor driven by theengine, a sensor configured to generate a first signal indicative of ademand for air pressure from the compressor and a second signalindicative of no demand for air pressure from the compressor. Theengine-driven power source also includes a controller configured to stopthe engine in response to the second signal.

DRAWINGS

These and other features, aspects, and advantages of the presentinvention will become better understood when the following detaileddescription is read with reference to the accompanying drawings in whichlike characters represent like parts throughout the drawings, wherein:

FIG. 1 is a diagram of a work vehicle having a service pack with a loadcontrol system in accordance with certain embodiments of the invention;

FIG. 2 is a diagram of an embodiment of power systems in the vehicle ofFIG. 1, illustrating support systems of the service pack separate andindependent from support systems of a vehicle engine;

FIG. 3 is a diagram of an embodiment of power systems in the vehicle ofFIG. 1, illustrating support systems of the service pack integrated withsupport systems of the vehicle engine;

FIGS. 4A-4C are diagrams of the service pack with different arrangementsof a generator, a hydraulic pump, and an air compressor driven by aservice pack engine in accordance with certain embodiments of thepresent disclosure;

FIG. 5 is a block diagram illustrating an embodiment of a power supplysystem for the service pack of FIGS. 1-4, wherein the power supplysystem includes a controller that is configured to receive signalsindicative of load demand from one or more components of the servicepack of FIGS. 1-4;

FIG. 6 is a process flow diagram illustrating an embodiment of anautomatic shutdown method performed by the controller of FIG. 5; and

FIG. 7 is a process flow diagram illustrating an embodiment of anautomatic startup method performed by the controller of FIG. 5.

DETAILED DESCRIPTION

As discussed below, embodiments of the present technique provide auniquely effective solution to power management and emissions control invarious applications. Thus, the disclosed embodiments relate or dealwith any application where a prime mover or power source that is enginedriven intermittently powers a load or combination of loads. In certainembodiments, the disclosed power control techniques may be used withvarious service packs to prevent unnecessary or wasteful emissions of adiesel engine power source that is directly coupled to multiple loads,specifically an air compressor, hydraulic pump, auxiliary AC electricgenerator that may be used intermittently (i.e., not substantiallycontinuously). For example, the disclosed embodiments may be used incombination with any and all of the embodiments set forth in U.S.application Ser. No. 11/742,399, filed on Apr. 30, 2007, and entitled“ENGINE-DRIVEN AIR COMPRESSOR/GENERATOR LOAD PRIORITY CONTROL SYSTEM ANDMETHOD,” which is hereby incorporated by reference in its entirety. Byfurther example, the disclosed embodiments may be used in combinationwith any and all of the embodiments set forth in U.S. application Ser.No. 11/943,564, filed on Nov. 20, 2007, and entitled “AUXILIARY SERVICEPACK FOR A WORK VEHICLE,” which is hereby incorporated by reference inits entirety.

As discussed below, the present embodiments utilize load sensing fromthe prime mover (e.g., engine) and/or individual loads to automaticallystart and/or stop the engine, thereby substantially reducing wastedenergy and emissions. The use of load sense from the prime mover and/orthe individual loads may include prime mover RPM monitoring orindividual output load sensing. The sensing (i.e., the representativesignals of each load) may be used to determine whether the primary powersource may be shut down or, alternatively, turned on. For example, incertain embodiments, a controller may acquire load information from theprime mover (e.g., engine). In addition, the controller may determinewhether battery power is sufficient to drive the sensed load or ifengine power is more appropriate. In situations where no load is sensedafter a period of time, the controller may shut the engine off.Alternatively and/or additionally, in situations where the engine is offand the controller senses that a load has been applied (e.g., a triggeror other throttle mechanism has been engaged), the controller mayinitiate an engine startup sequence.

Indeed, the present systems and methods are applicable to any number ofengine-driven power sources. One embodiment of the approaches describedherein may be applied to a work vehicle, such as a work vehicle 10depicted in FIG. 1. The work vehicle 10 is shown as a work truck,although the work vehicle 10 may have any other suitable configuration.In the illustrated embodiment, the vehicle 10 includes a service pack 12for supplying various services (e.g., electrical, compressed air, andhydraulic power) to a range of applications 14. As discussed in detailbelow, the service pack 12 includes an engine auto stop and auto startcontrol system and process configured to sense applied loads andautomatically start and/or stop an engine when appropriate. The vehicle10 has a main vehicle power plant 16 based around a vehicle engine 18.The main vehicle engine 18 may include a spark ignition engine (e.g.,gasoline fueled internal combustion engine) or a compression ignitionengine (e.g., a diesel fueled engine.

The vehicle power plant 16 includes a number of support systems. Forexample, the engine 18 consumes fuel from a fuel reservoir 20, e.g., oneor more liquid fuel tanks. An air intake or air cleaning system 22supplies air to engine 18, which may, in some applications, be turbocharged or super charged. A cooling system 24, e.g., a radiator,circulation pump, a thermostat-controlled valve and a fan, provides forcooling the engine 18. The vehicle power plant 16 also includes anelectrical system 26, which may include an alternator or generator,along with one or more system batteries 27. The vehicle power plant 16also includes a lube oil system 28, which may draw oil from the enginecrankcase, and circulate the oil through a filter and cooler, ifpresent, to maintain the oil in good working condition. Finally, thepower plant 16 includes an exhaust system 30, which may includecatalytic converters, mufflers, and associated conduits.

The service pack 12 may include one or more service systems driven by aservice engine 32. In a present embodiment, the service pack 12 provideselectrical power, hydraulic power, and compressed air for theapplications 14. In the diagrammatical representation of FIG. 1, forexample, the service engine 32 drives a generator 34 as well as ahydraulic pump 36 and air compressor 38. As discussed in detail below,the service pack 12 may detect the application of various loads (e.g.,via one or more load senses). Such loads that may be associated with theservice engine 32 can be sensed via a direct measurement of engine loadrelating to the service engine 32, a measurement of generator loadrelating to the generator 34, a measurement of hydraulic pump loadrelating to the hydraulic pump 36, and/or a measurement of compressorload relating to the air compressor 38. In response to the load sense,the service pack 12 may stop and/or start the service engine 32. Forexample, in order to provide power for each load, a control system,discussed in further detail below, in some embodiments, functions toturn on the engine 32 in situations where the power provided by one ormore batteries 27 or the generator 34 is not sufficient, or when theservice engine 32 is off. Further, the control system may turn off theservice engine 32 when appropriate, such as when the service engine 32has been running for some time and no load has been applied over apredetermined amount of time.

The generator 34 may be directly driven by the engine 32, such as byclose coupling the generator 34 to the engine, or may be belt or chaindriven, where desired. The hydraulic pump 36 may be based on anysuitable technology, such as piston pumps, gear pumps, vane pumps, withor without closed-loop control of pressure and/or flow. In certainembodiments, the pump 36 may include a constant displacement pump, avariable displacement pump, a plurality of pumps in a parallel or seriesconfiguration, or a combination thereof. The air compressor 38 may alsobe of any suitable type, such as a rotary screw air compressor or areciprocating piston air compressor.

The systems of the service pack 12 include appropriate conduits, wiring,tubing and so forth for conveying the service generated by thesecomponents to an access point, and for control by a control system.Convenient access points will be located around the periphery of thevehicle, such as access to a start button that may allow a user to turnon the service engine 32 after it has been automatically turned off.Alternatively and/or additionally, the start button may flash to alertthe user that the controller has begun a startup sequence of the serviceengine 32. In one embodiment, all of the services may be routed to acommon access point, although multiple access points can certainly beenvisaged. The diagrammatical view of FIG. 1 illustrates the generator34 as being coupled to electrical cabling 40 (for AC power supply) and41 (for 12 volt DC power supply). The hydraulic pump 36 is coupled tohydraulic circuit 42 and the air compressor 38 is coupled to an aircircuit 44.

As represented generally in FIG. 1, the generator 34 is also coupled tothe vehicle electrical system, and particularly to the vehicle battery27. Thus, as described below, not only may the service pack 12 allow for12 volt loads to be powered without operation of the main vehicle engine18, but the vehicle battery 27 may serve as a shared battery, and ismaintained in a state of charge by the service pack 12 generator output.Indeed, as described in further detail below, the control system maymonitor the level of charge of the vehicle battery 27 to ensuresubstantially continuous monitoring of applied loads, power consumption,and so forth.

The cabling and conduits 40, 41, 42 and 44 may, as in the illustratedembodiment, route service for all of these systems directly fromconnections on the service pack 12. In one embodiment, for example,connections are provided at or near a base of an enclosure of theservice pack 12, such that connections can be easily made without theneed to open the enclosure. Moreover, certain control functions may beavailable from a control and service panel 46. For example, the servicepanel 46 may be located on any surface of the vehicle 10, or on multiplelocations in the vehicle 10. The control and service panel 46 maypermit, for example, starting and stopping of the service engine 32 by akeyed ignition or starter button, or by a controller that is configuredto automatically start and/or stop the service engine 32 housed withinthe service panel 46. Other controls for the service engine 32 may alsobe provided on the control and service panel 46. The control and servicepanel 46 may also provide operator interfaces for monitoring the serviceengine 32, such as fuel level gages, pressure gages, as well as variouslights and indicators for parameters such as pressure, speed, and soforth. For example, in situations where the control system initiates anautomatic start, a light, such as an LED or similar feature, may blinkor flash to indicate that the service engine 32 has initiated a startupprocedure. The service panel 46 may also include a stop, disconnect ordisable switch (not separately shown) that allows the operator toprevent starting of the service pack engine 32, such as during transportor if the user does not desire for the service engine 32 to beautomatically started.

As also illustrated in FIG. 1, a remote control panel or device 46A mayalso be provided that may communicate with the control panel 46 ordirectly with the service pack 12 via cabling or wirelessly. In a mannersimilar to conventional crane or manlift controls, then, the operatormay start and stop the service pack engine 32, and control certainfunctions of the service pack 12 (e.g., engagement or disengagement of aclutched component, such as an air compressor) without directlyaccessing either the components within the service pack enclosure or thecontrol panel 46.

As noted above, any desired location may be selected as a convenientaccess point for one or more of the systems of the service pack 12. Inthe illustrated embodiment, for example, one or more alternating currentelectrical outputs, which may take the form of electrical receptacles 48(for AC power) and 49 (for 12 volt DC power) are provided. Similarly,one or more pneumatic connections, typically in the form of a quickdisconnect fitting may be provided as indicated at reference numeral 50.Similarly, hydraulic power and return connections 52 may be provided,which may also take the form of quick disconnect fittings.

In the embodiment illustrated in FIG. 1, the applications 14 may becoupled to the service pack 12 by interfacing with the outputs providedby receptacle 48. For example, a portable welder 54 may be coupled tothe AC electrical output 48, and may provide constant current orconstant voltage-regulated power suitable for a welding application. Thewelder 54 may receive power from the electrical output of the generator34, and itself contain circuitry designed to provide for appropriateregulation of the output power provided to cables suitable for a weldingapplication 56.

Similarly, DC loads may be coupled to the DC receptacle 49. Such loadsmay include lights 58, or any other loads that would otherwise bepowered by operation of the main vehicle engine 18. As mentioned above,the 12 volt DC output of the service pack 12 also serves to maintain thecharge of the vehicle battery 27, and to power any ancillary loads thatthe operator may need during work (e.g., cab lights, hydraulic systemcontrols, control system and load monitors, etc.).

The pneumatic and hydraulic applications may be similarly coupled to theservice pack 12 as illustrated in FIG. 1. For example, a hose 62 orother conduit may be routed from the compressed air source at the outlet50 to a tool, such as an impact wrench 60. Many such pneumatic loads maybe envisaged. Similarly, a hydraulic load, illustrated in the form of areciprocating hydraulic cylinder 64 may be coupled to the hydraulicservice 52 by appropriate hoses or conduits 66. Certain of theapplications illustrated diagrammatically in FIG. 1 may be incorporatedinto the work vehicle 10. For example, the work vehicle 10 may bedesigned to include a man lift, scissor lift, hydraulic tail gate, orany other driven systems, which can be coupled to the service pack 12and driven separately from the main vehicle engine 18.

In use, the service pack 12 may provide power for the on-siteapplications 14 substantially separately from the vehicle engine 18.That is, the service engine 32 generally may not be powered duringtransit of the vehicle 10 from one service location to another, or froma service garage or facility to a service site. Once located at theservice site, the vehicle 10 may be parked at a convenient location, andthe main engine 18 may be shut down. The service engine 32 may then bepowered to provide service from one or more of the service systems(e.g., generator 34, hydraulic pump 36, and air compressor 38) describedabove. The service pack 12 also may include clutches, or othermechanical engagement devices, for selective engagement anddisengagement of one or more of the generator 34, the hydraulic pump 36,and the air compressor 38, alone or in combination with one another.

Several different scenarios may be envisaged for driving the componentsof the service pack 12, and for integrating or separating the supportsystems of the service pack 12 from those of the vehicle power plant 16.One such approach is illustrated in FIG. 2, in which the service pack 12is independent and operates separately from the vehicle power plant 16.In the embodiment illustrated in FIG. 2, as shown diagrammatically, thesupport systems for the vehicle power plant 16 are coupled to thevehicle engine 18 in the manner set forth above. The service pack 12reproduces some or all of these support systems for operation of theservice engine 32. In the illustrated embodiment, for example, thesesupport systems include a separate fuel reservoir 70, a separate aircleaner system 72, a separate cooling system 74, a separate electricalprotection and distribution system 76, a separate lube oil system 78,where desired for the engine, and a separate exhaust system 80.

Many or all of these support systems may be provided local to theservice engine 32, that is, at the location where the service engine 32is supported on the vehicle 10. On larger work vehicles, access to thelocation of the service engine 32 and the service pack 12 in general,may be facilitated by the relatively elevated clearance of the vehicle10 over the ground. Accordingly, components such as the fuel reservoir,air cleaner, cooling system radiator, electrical fuse box, and so forthmay be conveniently positioned so that these components can be readilyserviced. Also, in the illustrated embodiment, the hydraulic pump 36 andair compressor 38 are illustrated as being driven by a shaft extendingfrom the generator 34, such as by one or belts or chains 68. As notedabove, one or both of these components, or the generator 34 may beprovided with a clutch or other mechanical disconnect to allow them toidle while other systems of the service pack are operative.

FIG. 3 represents an alternative configuration in which the service packsupport systems are highly integrated with those of the main vehiclepower plant 16. In the illustration of FIG. 3, for example, all of thesystems described above may be at least partially integrated with thoseof the vehicle power plant 16. Thus, coolant lines 82 are routed to andfrom the vehicle cooling system 24, while an air supply conduit 84 isrouted from the air intake or cleaner 22 of the vehicle engine.Similarly, an exhaust conduit 86 routes exhaust from the service engine32 to the exhaust system 30 of the vehicle engine 18. The embodiment ofFIG. 3 also illustrates integration of the electrical systems of thevehicle 10 and the service pack 12, as indicated generally by theelectrical cabling 88 which routes electrical power to the distributionsystem 26 of the vehicle. The systems may also integrate lube oilfunctions, such that lubricating oil may be extracted from both crankcases in common, to be cleaned and cooled, as indicated by conduit 90.Finally, a fuel conduit 92 may draw fuel from the main reservoir 20 ofthe vehicle, or from multiple reservoirs where such multiple reservoirsare present on the vehicle.

In some embodiments, integrated systems of particular interest includeelectrical and fuel systems. For example, while the generator 34 of theservice pack 12 may provide 110 volt AC power for certain applications,its ability to provide 12 volt DC output is particularly attractive tosupplement the charge on the vehicle batteries, for charging otherbatteries, and so forth. The provision of both power types, however,makes the system even more versatile, enabling 110 volt AC loads to bepowered (e.g., for tools, welders, etc.) as well as 12 volt DC loads(e.g., external battery chargers, portable or cab-mounted heaters or airconditioners, etc.).

In certain embodiments, a system may include an integration solutionbetween those shown in FIG. 2 and FIG. 3. For example, some of thesupport systems may be best separated in the vehicle 10 both forfunctional and mechanical or flow reasons. The disclosed embodimentsthus contemplate various solutions between those shown in FIG. 2 andFIG. 3, as well as some degree of elimination of redundancy betweenthese systems. In a presently contemplated embodiment, at least some ofthe support systems for the primary vehicle engine 18 are used tosupport the service pack 12 power plant. For example, at least the fuelsupply and electrical systems can be at least partially integrated toreduce the redundancy of these systems. The electrical system may thusprovide certain support functions when the vehicle engine is turned off,removing dependency from the electrical system, or charging the vehiclebatteries 27. Similarly, heating, ventilating and air conditioningsystems may be supported by the service pack engine 32, such as toprovide heating of the vehicle cab when the primary engine 18 is turnedoff. Thus, more or less integration and removal of redundancy ispossible. It should be noted that any of the loads described above maybe monitored, further including, for example, air conditioning, heat,various support systems, and so on. As such, the methods of powercontrol as described herein may also include an automatic start and/orstop of the vehicle engine 18 in addition to or in lieu of the serviceengine 32. For example, in embodiments where the vehicle engine 18 isturned off and many loads are being applied to the service engine 32,the controller may automatically start the vehicle engine 18 to avoid orat least mitigate the possibility of engine overload.

The foregoing service pack systems may also be integrated in anysuitable manner for driving the service components, particularly thegenerator 34, hydraulic pump 36, and air compressor 38, and particularlyfor powering the on-board electrical system, including a control systemor similar feature. Accordingly, any of these may be automaticallystopped and/or started in accordance with the embodiments disclosedherein. FIGS. 4A-4C illustrate diagrams of certain implementations fordriving these components from the service engine 32. In the embodimentillustrated in FIG. 4A, the generator 34 may be close-coupled to theoutput of the engine 32, such as directly to the engine fly wheel or toa shaft extending from the engine 32. A sheave 94 is mounted to anoutput shaft extending from the generator, and similar sheaves 96 and 98are coupled to the hydraulic pump 36 and air compressor 38. One or morebelts 38 and/or clutches are drivingly coupled between these components,and an idler 100 may be provided for maintaining tension on the belt.Such an arrangement is shown in FIG. 4B, in which the hydraulic pump 36is driven through a clutch 102, such as an electric clutch. It should benoted that any one of the components may be similarly clutched to allowfor separate control of the components. Further, in one embodiment, theautomatic start and/or stop control may operate by controlling theseservices through their respective clutches. Such control may be usefulfor controlling the power draw on or the output by the engine 32, forexample when no load is drawn from the particular component over aperiod of time, and when the component is not needed for support of themain vehicle engine systems (e.g., maintaining a charge on the vehiclebatteries).

These components may be supported in any suitable manner, and maytypically include some sort of rotating or adjustable mount such thatthe components may be swung into and out of tight engagement with thebelt to maintain the proper torque-carrying tension on the belt andavoid slippage. More than one belt may be provided on appropriatemulti-belt sheaves, where the torque required for turning the componentsis greater than that available from a single belt. Other arrangements,such as chain drives, may also be envisaged. Moreover, as describedabove, the generator 34 may also be belt or chain driven, or more thanone component may be driven directly by the engine 32, such as in anin-line configuration. In other arrangements, one or more of thecomponents may be gear driven, with gearing providing any requiredincrease or decrease in rotational speed from the output speed of theengine 32, such as during an automatic startup or shutdown sequence. InFIG. 4C, a support adapter 104 mounts the generator 34 on the serviceengine 32, and the hydraulic pump 36 and air compressor 38 are driven bya gear reducer.

The particular component or components that are directly and/orindirectly driven by the engine 32 may be selected based upon thecomponent and engine specifications. For example, it may be desirable todirectly drive the hydraulic pump 36, and to drive the generator 34 viaa belt or gear arrangement, permitting the engine 32 to operate at ahigher speed (e.g., 3000 RPM) while allowing a reduced speed to drivethe generator (e.g., 1800 RPM for near 60 Hz AC output of a 4 polegenerator). Indeed, in such configurations, it may be possible toautomatically start and/or stop each of these by way of the serviceengine 32.

FIG. 5 is a block diagram illustrating an embodiment of a power supplysystem 100 for the service pack 12 of FIGS. 1-4. As illustrated, thepower supply system 100 includes a controller 102 operatively connectedto and interfaced with the prime mover or service engine 32, the aircompressor 38, the hydraulic pump 36, and the generator 34. Thecontroller 102 may optionally be coupled to a load sense 104 that isconfigured to interface with components of the compressor 38, thehydraulic pump 36, the generator 34, and the engine 32. In oneconfiguration, the controller 102 may receive (optionally via the loadsense 104) information from the service engine 32 (such as RPMfeedback). In situations where the service engine 32 is on for anextended period of time with no applied load (such as no change in theRPM feedback), the controller 102 may initiate a shutdown sequence ofthe service engine 32 and, in some situations, the power supply system100. Additionally and/or alternatively, the controller 102 may receive,optionally via the load sense 104, information such as a pressure change(e.g., a pressure drop of a compressor storage tank) or an electricaldraw, from a load 106 of the compressor 38, a load 108 from thehydraulic pump 36, a load 110 from the generator 34, and so on. Further,the load sense 104 may be communicatively coupled with a load control112 of the compressor 38, a load control 114 of the hydraulic pump 36,and a load control 116 of the generator 34. In such implementations, theload sense 104 may detect throttle positions, pressure regulatorchanges, changes in electrical potential, and so forth.

For example, each component and its respective load and/or load controlmay provide at least two signals to the controller 102 (e.g., via theload sense 104 or other sensor). One signal may be considered a loaddemand while the other signal may be considered an absence of loaddemand. As an example, a first signal may be provided to the controller102 that is indicative of a demand for air pressure from the compressor36 (such as a decrease in a pressure of a compressor storage tank),while a second signal is provided to the controller 102 that isindicative of no demand for air pressure from the compressor 36 (such asa substantially constant valve of the pressure over a given time). Thesame may be true for all of the components operatively connected to thecontroller 102. Thus, the controller 102 may receive first and secondsignals from the hydraulic pump 36 indicative of a hydraulic demand forhydraulic pressure (e.g., a decrease in hydraulic pressure from thepump) and no hydraulic demand for hydraulic pressure (e.g., asubstantially constant value of the hydraulic pressure over a giventime), respectively. Similarly, the controller 102 may receive first andsecond signals from the generator 34 indicative of electrical demand forelectrical power and no electrical demand for electrical power,respectively.

In operation, the controller 102 may substantially continuously receivesuch signals, such that a combination of demand and no demand signalsare received from the compressor 38, the hydraulic pump 36, and thegenerator 34 to provide first, second, third, fourth, fifth, and sixthsignals. It should be noted that the terms first through sixth are notintended to denote any sequence in time, space, or any other parameter,and are used to facilitate discussion of the present techniques.Accordingly, any one of the components of the system 100 may provide afirst, second, third, fourth, fifth, or sixth signal, and so on.Further, the controller 102 is coupled to the battery 27 to ensuresufficient charge for normal operation and sensing. In embodiments wherethe controller 102 receives a no demand signal from each component for agiven time, such as about 5 minutes (e.g., about 1, 2, 5, 10, or 15minutes), which may be considered a first time period, the controller102 may initiate a shutdown sequence of the service engine 32, butmaintain itself in an “on” state (e.g., powered by battery 27), wherethe controller 102 is able to monitor applied loads. Indeed after anextended period of time, such as after greater than about 15 minutes(e.g., about 15, 20, 25, 30, 40, 45 minutes or more), which may beconsidered a second time period, the controller 102 may initiate ashutdown sequence that results in the controller 102 being placed in an“off” state (e.g. not powered at all), where no monitoring is performed.It should be noted that in such instances, a user may turn the powersupply system 100 back on by pressing a start button, keying anignition, or any similar act.

In situations where the controller 102 receives signals indicative ofdemand while the service engine 32 is running, the controller 102 maytake no action. However, in situations where the service engine 32 isoff but the controller 102 is still monitoring loads (e.g., after thefirst time period but before the second) and the controller 102 receivessignals indicative of demand, the controller 102 may initiate a startupsequence of the service engine 32. Such a startup sequence may include awarning (e.g., visual or audible) to the user that the service engine 32is about to be turned on. In such situations, the user may prevent theservice engine 32 from being turned on by, for example, a killswitch orsimilar mechanism.

The controller 102 may contain processing components configured toperform the tasks described above. For example, the controller 102 maycontain one or more processing components configured to execute one ormore algorithms capable of performing such load sensing and powercontrol functions. Accordingly, the present embodiments provide a methodor sequence 160 of automatically shutting down the service engine 32,which is depicted as a process flow diagram in FIG. 6. While theautomatic shutdown sequence 160 is described in the context of the powersupply system 100 and, by extension the service pack 12, it should benoted that the methods disclosed herein are also applicable to otherpower supply schemes, such as any power supply utilizing an engine todrive one or more loads. The method 160 includes a step of monitoringthe system (such as system 100 of FIG. 5), where the controller 102monitors, optionally via the load sense 104 or other sensor, the serviceengine 32 for power draw (i.e., a demand for power), or monitors theloads or load controls of each component (block 162). For example, thecontroller 102 may receive, substantially constantly, the first and/orsecond signals described above with respect to FIG. 5.

Substantially concurrently to performing such monitoring functions, thecontroller 102 may determine whether a load has been applied, or whetherthere has been a signal representative of demand from any of thecomponents that are operatively connected to the service engine 32(block 164). For example, the controller 102 may perform a timingfunction to determine how long it has been since a load has been appliedor a signal representative of a load demand has been received. Thesensed load can be applied to the battery 27, for example if the engine12 or 32 is off and the battery 27 is able to provide a suitable amountof energy for the applied load. In one embodiment, such power provisionby the battery 27 may obviate the need to turn on the engine 32. Assuch, the load handled by the battery may not be considered as a loadrequiring startup. Additionally or alternatively, the sensed load mayreach a threshold value, for example a threshold of required poweroutput that the battery 27 is unable to handle. Indeed, the load sensemay also include a determination as to whether the battery 27 hassufficient remaining charge to continue powering an applied load whilethe engine 32 is off. As an example, the applied load may reduce thecharge to approximately 5, 10, 15, or 20% of full charge. Upon reachingsuch a set charge level, the controller may sense an actual loadapplication requiring startup of the engine 32. In embodiments where aload demand signal has been received within the first time period (e.g.,within about 1, 5, 10, or 15 minutes), the method 160 may return toblock 162, where the controller 102 monitors the system 100 for anychanges in load demand and so forth.

In embodiments where there has not been a signal indicative of a loaddemand (i.e., substantially constant reception of signals indicative ofno load from all components) within the first time period, the method160 progresses to another step where the controller 102 determineswhether the charge on the battery (such as battery 27 of FIG. 5) issufficient to allow the controller 102 to perform monitoring withoutbeing powered by the generator 36 and/or service engine 32 (block 166).Further, the battery 27 may provide power to various service packfeatures while the service engine 32 begins a startup sequence, asdescribed below. In embodiments where the battery 27 is determined notto have acceptable charge (e.g., a voltage within a set specification),the method 160 may provide for the controller 102 to continue operatingthe engine 32 while monitoring the system 100 (block 162) until thebattery 27 reaches a suitable charge level.

Once the battery 27 has reached a suitable charge (e.g., the voltage iswithin a set specification) and no load has been sensed, the method 160may provide for the controller 102 to perform an automatic stop orshutdown of the service engine 32 (block 168) while keeping thecontroller 102 active (e.g., battery powered) to perform the monitoringfunctions described above. Accordingly, the controller 102 continues tomonitor the system 100 (block 170). The controller 102 may thendetermine whether a load has been applied during the second time periodfor example, after about 15, 20, 25, 30, 35, 40, 45 minutes or moretotal, including the first time period (block 172). If no signalindicative of a load demand has been received by the controller 102within the second time period, the controller 102 may initiate ashutdown of the entire system 100 (block 176), including the controller102 itself. Accordingly, if the user desires to utilize the power supplysystem 100 thereafter, the user may manually start the system 100, forexample by depressing a start button or keying an ignition. It should benoted that in such situations, such as at manual startup, the entiresystem 100 may initially be powered by the service engine 32.

Conversely, if the controller determines that a load has been applied tothe system 100 (e.g., the controller 102 receives a signal indicative ofdemand from any one of the components of the system 100) within thesecond time period, the controller 102 may initiate a startup sequence(block 174) of the service engine 32. It should be noted that such anact may be performed when the signal indicative of demand is received(i.e., within a few seconds of receiving the signal), such that theservice engine 32 is able to provide the desired power in a timelymanner. The startup sequence may include a number of acts performed bythe controller 102, including providing a warning to the user (e.g.,visual and/or audible) that the startup sequence has been initiated,among others. As an example, the visual indication may include one ormore blinking lights, a blinking startup button, the lights on theservice vehicle 10 may flash, and so on. The audible indication mayinclude a series of beeps of the same or different volumes emitted by,for example a separate speaker, or a horn of the service vehicle mayprovide the audible indication, such as a series of honks that isindicative of impending startup. The automatic start sequence isdescribed in further detail below with reference to FIG. 7, which is aprocess flow diagram of an automatic start sequence or method.

It should be noted that the automatic start sequence or method 180 maybe performed by the controller 102 either in concert with orsubstantially independent of the automatic shutdown method 160 describedabove. That is, the controller 102 may be configured to perform only theautomatic shutdown sequence 160, only the automatic start sequence, or acombination of both. Accordingly, while the automatic startup sequence180 is described as a set of acts performed during or after theautomatic shutdown sequence 160 in the present disclosure, it should benoted that the controller 102 may perform such acts in an independentmanner as well.

Accordingly, the sequence 180 may provide for the controller 102 tomonitor the system 100 (block 182), such as for signals indicative ofload demand. The controller 102 also determines whether the serviceengine 32 is running (block 184). In situations where the controller 102determines that the engine is running, the method 180 may provide forthe controller 102 to cycle back to block 182 to continue monitoring thesystem 100. If the controller 102 determines that the engine 32 is notrunning, for example in situations where the controller 102 is runningsubstantially only on power provided by the battery 27, the controller102 makes a further determination as to whether a load has been applied(block 186), for example, within the first time period described abovewith respect to FIGS. 5 and 6. In situations where the controller 102determines that no load has been applied (e.g., only signals indicativeof no load demand have been received), the controller 102 may continuemonitoring the system 100 (block 182).

However, in embodiments where the controller 102 determines that a loadhas been applied, for example if the controller 102 receives a signalindicative of a load demand within the first time period, the controller102 may provide an indication to the user (block 188) that the serviceengine 32 startup has been initiated. The indication may be a flashingstart button, such as a start button on the control panel 46 (FIG. 1),or may be an audible alert, or a combination of both. The indication maylast for a time that is specified by the user or the manufacturer. As anexample, the indication may last less than about one minute, such asabout one minute, or about 45, 40, 35, 30, 25, 20, 15, 10, or 5 seconds.In such a timeframe, the user may choose to abort the automatic start,or may choose to initiate the startup substantially immediately, suchthat the time between load application and startup is reduced.

Nevertheless, after the engine start indication has been provided (block188), the controller 102 may then initiate the engine autostart (block190). The autostart initiation may include the controller 102 providinga start signal to the engine 32 (or an engine controller). Once theengine 32 is started, the system 100 may perform normal power supplyfunctions (block 192).

While only certain features of the invention have been illustrated anddescribed herein, many modifications and changes will occur to thoseskilled in the art. It is, therefore, to be understood that the appendedclaims are intended to cover all such modifications and changes as fallwithin the true spirit of the invention.

The invention claimed is:
 1. A system, comprising: an engine; a batteryoperably coupled to the engine to provide power for starting the engine;a welder generator driven by the engine; an air compressor driven by theengine; a sensor configured to generate a signal indicative of whether ademand is made for air pressure from the air compressor by reference topressure in a compressed air storage tank; and a controller configuredto stop the engine when no demand is detected for welding power or forair pressure from the air compressor for a first predetermined time, andto restart the engine in response to determination that a state ofcharge of the battery is below a predetermined level, wherein thecontroller is configured to shut down its operation if no demand isdetected for a second predetermined time following stopping of theengine.
 2. The system of claim 1, wherein the controller is configuredto restart the engine in response to detection of a demand for airpressure from the air compressor.
 3. The system of claim 1, wherein thesignal indicates a decrease in a pressure of the compressed air storagetank.
 4. The system of claim 1, wherein the controller is configured toinitiate a startup sequence in response to the low battery charge state,and the startup sequence comprises a user warning followed by anautomatic engine start after a time period.
 5. The system of claim 1,wherein when the engine is restarted in response to determination thatthe state of charge of the battery is below a predetermined level, theengine is maintained running until the battery charge state reaches adesired level.
 6. The system of claim 1, wherein the controller isconfigured to restart the engine in response to determination that astate of charge of the battery is below 5, 10, 15, or 20% of fullcharge.
 7. The system of claim 1, wherein the controller is configuredto initiate a user-perceptible alarm prior to restarting the engine. 8.The system of claim 7, wherein the user-perceptible alarm comprises anaudible alarm.
 9. The system of claim 1, wherein the controller isconfigured to receive a user restart abort command and to abort therestart of the engine if the command is received.
 10. A system,comprising: an engine; a battery operably coupled to the engine toprovide power for starting the engine; a welder generator driven by theengine; an air compressor driven by the engine; a sensor configured togenerate a signal indicative of whether a demand is made for airpressure from the air compressor by reference to pressure in acompressed air storage tank; and a controller configured to stop theengine when no demand is detected for air pressure from the aircompressor for a first predetermined time and no welding generatordemand is detected, and to restart the engine in response to adetermination of any one of (1) a state of charge of the battery isbelow a predetermined level, (2) a demand for air pressure from the aircompressor, and (3) a demand for welding power, is detected, wherein thecontroller is configured to shut down its operation if no demand isdetected for a second predetermined time following stopping of theengine.
 11. The system of claim 10, wherein the signal indicates adecrease in a pressure of the compressed air storage tank.
 12. Thesystem of claim 10, wherein when the engine is restarted in response todetermination that the state of charge of the battery is below apredetermined level, the engine is maintained running until the batterycharge state reaches a desired level.
 13. The system of claim 10,wherein the controller is configured to restart the engine in responseto determination that a state of charge of the battery is below 5, 10,15, or 20% of full charge.
 14. A method, comprising: driving a weldergenerator and an air compressor via an engine, the engine beingoperatively coupled to a battery to provide power for starting theengine; sensing whether a demand is made for air pressure from the aircompressor by reference to pressure in a compressed air storage tank;automatically stopping the engine, via control circuitry, when no demandis detected for air pressure from the air compressor for a firstpredetermined time and no welding generator demand is detected;automatically restarting the engine, via the control circuitry, inresponse to a determination of any one of (1) a state of charge of thebattery is below a predetermined level, (2) a demand for air pressurefrom the air compressor, and (3) a demand for welding power, isdetected; and shutting down the control circuitry if no demand isdetected for a second predetermined time following stopping of theengine.
 15. The method of claim 14, comprising providing a user warningfollowed by an automatic engine start after a time period.
 16. Themethod of claim 14, comprising restarting the engine in response todetermination that a state of charge of the battery is below 5, 10, 15,or 20% of full charge.
 17. The method of claim 14, comprising generatinga user-perceptible alarm comprises an audible alarm prior to restartingthe engine.
 18. The method of claim 14, comprising receiving a userrestart abort command and aborting the restart of the engine if thecommand is received.
 19. The system of claim 10, wherein the controlleris configured to initiate a user-perceptible alarm prior to restartingthe engine.
 20. The system of claim 10, wherein the controller isconfigured to receive a user restart abort command and to abort therestart of the engine if the command is received.